Animal-free milk or cowless milk is non-dairy milk made by inserting cow genes into microbiota like yeast. The inserted genes are able to encode the protein casein and whey proteins, the major proteins found in milk (Newman et al., 2021). This brilliant idea was originally discovered and developed by Perfect Day, a food technology startup company in California that focuses on creating milk proteins via microbiota fermentation (Loike, 2018). In animal-free milk production, sugar as nutrients is added into microbiota culture grown inside bioreactors. This genetically modified microbiota then converts the sugar through precision fermentation, a process that utilizes microorganisms to produce specific and pure compounds, which in this case are milk proteins. After enough milk proteins are produced, they are separated from the microbiota, filtered, purified, and finally dried. The end product is a milk protein powder ready to be used to make milk (Donaldson & Carter,2016; Perfect Day, 2022a). What is interesting is that this powder can also be used to make milk-derived products such as ice cream, cheese, cream cheese, and yogurt. These products have been marketed by Perfect Day in collaboration with Urgent Company under different brands (Perfect Day, 2022b). As an animal-free food, animal-free milk is claimed to be more environmentally friendly as its production saves up to 98% water, 99% sea water consumption, 60% non- renewable energy, and reduces greenhouse gas emissions by up to 97% (Perfect Day, 2021). This milk also provides solutions for those who are concerned about how cows are treated in conventional milk production (Milburn, 2018). There is also little to no chance of contamination from bacteria inside the cow’s system and cow milk production-related contaminants including antibiotics, hormones, and pesticides. Additionally, using microbiota to produce cultured milk allows for manipulating the composition of the milk such as adding certain proteins and fats or excluding undesired compounds like lactose and cholesterol. This gives the capacity to make the milk more creamy, protein-rich, flavorful, and less harmful (Donaldson & Carter, 2016). As animal-free milk does not contain lactose, it is safe to be consumed by lactose-intolerant people. However, it needs to be noted that animal-free milk can still cause milk allergies as it contains proteins similar to cow milk (Loike, 2018). Looking at these promising advantages, it is evident that animal-free milk has the potential to thrive in the market and should be introduced to the public. Although animal-free milk has tons of adva tages, its exact quality, safety, and side effects still need to be investigated as this technology is still under development. Also, the microbiota does not
have the ability to produce specialized enzymes – like the ones made inside the mammary cells of cows – that add other compounds like calcium phosphate to their produced casein. This raises questions about whether the contents and functionalities of animal-free milk fully represent the ones in cow milk and challenges producers to replicate accurate milk synthesis in terms of their structure (Holt et al., 2013). This imperfection surely will give room for animal-free milk to undergo further testing and spark lots of interest in researchers and those who work in the business field. With constant efforts and support from society, there is a chance for animal-free milk to replace cow milk in the future dairy industry.